Pickup with two needles



Aug. 23, 1949.` E. F. ANDREWS PICKUP WITH Two NEEDLES l Filed Feb. 11, 1942 Patented Aug. 23, 1949 PICKUP WITH TWO NE'EDLES Edward F. Andrews, Chicago, Ill., assigner, vby ;mesne assignments, to N. `Marshall Seeburg,

Chicago, Ill.

Application February 11, 1942, Serial No.430,'337

(Cl. 27d-$6) 7 Claims.

The present invention pertains to pickups and particularly -to pickups forplaying opposite sides of double faced discrecords and this application is a continuation iin part-of my copendlng application, ASerial No. 346,105, led July v18, 1940, patented July 6, 1'94'3, No.'2,323,`365.

In my copending application, there is disclosed an automaticvphoncgraph Lcapable of selectively playing both sides vof Adouble faced disc records.

To accomplish this, the pickup is bodily transi lated from one side Of-a record playing position to the other, its pat-h of movement being along a line substantially parallel tothe laxis of rotation of the record so thatvwhen Vone side of a record is being played, one -side of the pickup faces toward the record playing plane and when the other side is playedfthe yother side of the pickup faces toward `-the other side 'of the plane.

The primary object of the 'present invention is the 'provision of a new 'andimproved pickup having Vrecord engagingfneedle point defining portions extending in opposite directions from the pickup for Aengagement with opposite sides of records.

Another object of "thepresent invention is the i provision of a'n'ew `andimproved pickup having record engaging `4needle point defining portions extending in'opposite ldirections from 'the pickup through `openings in the pickup casing for engagement'with opposite sides of records.

A further object of the Iinvention is the provision of a new and improvedpickup of the type mentioned wherein the point dening portions are constituted by a single double pointed needle, and, further, wherein the needle is located at a slant Vrelative :to lthe Yrecord surface.

Another object ofthe `invention is the provision ofanew andimprcvedpickup wherein oppcsitely extending needles are Vdetachably-mounted in a single chuck by means of a single securing means.

A-further object oftheinvention is the provision of a new and improved `pickup comprising a Aneedle holding "chuck adapted removably to receive needles as by apress fit.

A further object of the invention is theprovisioncf a new and improved pickup wherein the needle points lie in 4substantially 'the same plane transversely of the pickup yand on opposite sides of the pickup, whereby-the two points are located equidistantffrom Athe pivot 'point about which the pickup moves when a record is played. This arrangement provides Ya mini-mum needle tracking error forboth sides of the record.

A further object o'f the invention is the provision of double needle point pickups-having small `.2 mass, thereby increasing the resonance frequency of the pickup 'andproviding1ibetter 'reproduction of high-frequency' vibrations.

A further object -of-zthe invention 'is to provide a new and improved tone ar-rnfand pickup `assembly wherein the pickup 4constitutes an extension cf the tone arm. i

Further objects and advantages of the present invention will'lbecomezapparent ifromthe ensuing description in the vcourse (5f-which Areference is had to the accompanying drawing, inrwhich:

Fig. `1 shows a .pickupfand tone Iarm assembly constructed in accordancewith'the present invention; the solid "line'gures :illustrating the assembly in playing position onrone side yof a record vand the Yphantom iinesillustrating the assembly in playing'po'sition onlthe other side of the record;

Fig. 2 is an lenlarged central .cross-sectional view of the assembly,fth'eyiewbeingtaken'along the lineZ---il of lFiggS;

Fig. 3 is a cross-sectionalvewtaken along the line 3--3 of Fig-2; i

Fig. 4 is a fragmentaryv crosss-ectional view of a modied "form-ofpickup wherein coaxially located needles are removably secured to a needle chuckby prcsslfits;

Fig. 5 isra view similarto Fig. 4 of a further modification vwherein the needles `are secured directly to -a `coupling member connected tc the transducer in such manner fthat the needle points are'located at 'opposite-sides of the Apickup in substantia'lly-the same plane transverse ofthe pickup; and

Fig. 6 is a cross-sectional -v'iew of a `further modiiication wherein Loppos'itely extending needies are located in substantially side by side relationshipand held `in place fbyla single securing means.

Referring now toi-Figs. 1, "2, and 3, and more particularly to Fig. `1,'i-tmaybe'noted thatthe pickup and tone armassernbly comprises a pickup lil secured to the `outer-end of the tone arm i2 in such a manner fas to constitutelan extension of the tone arm. A single Adouble Vpointed needle lil. the opposite `lends 4It and 118er which project outside and beyond-'opposite sides of the pickup structure, is removably secured to thefpickup by means of a single thumb-screw 20.

In Fig. 1, the `pickup fand 4tene yarm assembly is shown in solidflinesimposition-to play the right side of a double ifaceti disc'recordfZZ. At this time the needle point IE is in `engagement with the record lgrooves lon therigl'it sidefofi-the record. When the leit side-diria frecordliis lto be played,

the pickup and tone arm is shifted bodily to the left along a line parallel to the axis of rotation of the record so that the needle point I8 can be brought into engagement with the left side of a record. It should be noted that the needle I4 is located at a slant relative to the pickup and the record so that the needle points slant in the direction of Vrotation of the record (indicated by the arrows R and L) irrespective of the side of the record being played.

The construction of the pickup is illustrated more particularly in Figs. 2 and 3 to which refer.- ence will now be had. It comprises a supporting structure or casing made of two opposed parts 24 and 26, secured together by a plurality of suitably located flat-headed screws 2B. A transducer including a mechanically actuated element, in this case a piezo-electric crystal 38, is mounted within the hollow central portion 3l of the casing between a pair of rubber pads 32. To the lower end of the crystal are secured relatively flat conductors 34 connected in turn to terminals 36 mounted on a block 38 of insulating material held in place between the casing parts 24 and 26. The conductors are insulated from the pickup casing by insulating strips 39. The terminals 35 are located within the hollow portion 40 of the tone arm I2.

The movement of the needle is transmitted to the piezo-electric crystal by means of a coupling member, in this case a torsion wire 42 of suitable characteristics and extending upwardly from the crystal into a hollow portion 44 dened by opposed relatively narrow channels in the casing parts Y Z41and 26. The coupling member is suitably secured to the upper end of the crystal by a channel-shaped member 46 encircling a portion of the upper end of the crystal. It should be understood that other forms of transducers may be utilized in place of the piezo-electric crystal.

The needle I4 is secured to a chuck indicated generally by reference character 48. The chuck is drilled or otherwise formed with an opening to receive the upper end of the torsion wire 42. The. upper end 50 of the chuck is hollowedout in a suitable manner as by drilling and threaded internally to receive the thumb screw 20. The chuck isalso providedv with slantingbosses 52 which are drilled at a slant to receive the needle, the opening thus formed passingthrough the axis of rotation of the coupling member 42. The needle is preferably grooved centrally, as indicated by the reference character 54, so that the pointed end of the thumb screw may cooperate therewith to center the needle.

The two casing parts are also drilled'at the same angle as the needle receiving opening in the chuck, as indicated by reference characters 56, so that the needle points may extend to points beyond andclear of the casing. The chuck is mounted in spaced apart rubber bearings 58 located near the opposite endsvof the chuck in the hollow 44. An advantage resulting from the use of a single needle and a chuck such as that illustrated in Figs. 1 to 3 is that the overall length of the bosses 52 need not be any longer than if a single point needle was employed.

One of the features of the present invention is, as has already been indicated, the provision of a pickup and tone arm assembly wherein the pickup constitutes an extension of the tone arm. This construction may be readily noted from Figs. 1, 2, and 3 wherein the pickup is connected to the outer end of the tone arm by means of a tongue I!) formed at the inner end of the pickup 4 and a slot IU2 formed at the outer end of the tone arm. The outer end of the tone arm may be slotted as indicated by the reference character 84 (see Fig. 1) in order to provide ilexibility better to enable the pickup to be clamped to the tone arm.

In the modification of the invention illustrated in Fig. 4, two oppositely extending coaxially arranged needles i and 62 are employed and these are detachably secured as by a press fit in the oppositely extending slotted and apertured portions 64-and 66 of a chuck indicated generally by a reference character E8. The apertured portions 64 and 66 of the chuck and the needles Sil and 62 extend into and pass through slanting openings 88 in the pickup casing parts. The chuck in this modication is secured directly to the coupling member 42 which passes through a suitable opening in the chuck, which opening intersects the axis of the needles E0 and 62. The chuck is secured directly to the torsion wire as by welding or soldering. The upper end of the torsion wire'is secured by spaced apart rubber bearings 'l0 mounted in the hollow 44.

A pickup constructed in accordance with this modification has a very small mass and requires but a relatively short extension of the coupling member for mounting the needles since the bearings 70 may be brought relatively close together.

In the modification of the invention illustrated in r 'g. 5, the oppositely extending needles l2 are so mounted that the points lie in the same plane transverse of the axis of rotation of the torsion wire 42 and the axes of the needles are substantially` parallel to each other and intersect the axis of the torsion wire 42. In the construction herein illustrated, the torsion member is extended as in the last described embodiment and supported by spaced apart rubber bearings 14. The inner ends of the needles are provided with drilled bosses I6 through which the coupling member extends and these bosses are secured to the coupling member in suitable manner as by welding or soldering. The casing is drilled as indicated by reference characters 'I8 to enable the needles to pass through the casing parts and to project beyond and clear of the pickup. An advantage of this construction is its light mass and a fur ther advantage results from having the needle points in the same plane, so that distance from the pivotal point of the tone arm to the needle points is the same irrespective of the side of a record being played, which is of especial advantage when the major axis of the pickup and the transducer actuating member 42 is located at an angle to the axis of the tone arm I2 such that the needle end of the axis of the actuating member or element is nearer the center of the turntable than the opposite end when the pickup is in playing position, thereby to reduce the tracking error during the playing of records. n View oi" the permanent connection of the needles to the torsion wire, the needles should be provided with permanent points of sapphire or hard alloy or the like and as indicated by reference characters 19.

In the embodiment of the invention illustrated in'Fig. 6, the oppositely projecting needles 80 and 82 are mounted side by side in a chuck, indicated generally by the reference character 84, having jan integral portion coupling the chuck to the transducer 3i). The chuck is mounted near the outer end of the pickup in a pair of spaced apart rubber bearings 88. It comprises a central hollow portion located at a slant relative :envases the chuck. 11n vthe .event round :shank in'eedles K are utilized, it 4is .preferable `to iutilize a .spacer @il located ibetween .the .needles fso that fivhen :the needle securing.thumb screw 236 .is tightenedjthe needles a1e secnrelyheldin lplace. In theleyent 1 i square shank needles are utilized, a spacer need not be utilized as the two needles will be securely held in place by the force applied through the outer needle to the inner needle. The central portion of the chuck, i. e., the needle holding portion is surrounded by rubber bearings 98 located therebetween and the adjoining portions of the casing.

Although the present invention has been disclosed in conjunction with specific details of preferred embodiments thereof, it should be understood that these detailed constructions are not intended to be limitative of the invention except in so far as set forth in the accompanying claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. A pickup for playing opposite sides of double faced disc records, including in combination, a support, a transducer including a mechanically actuated element mounted on said support, an elongated coupling member for mechanically ac tuating said element, said coupling member being mounted on said support for limited rotation about an axis located lengthwise of the pickup and connected to said element, and means for imparting movement to said coupling member when either side o said pickup is brought into position to engage a record, said last-mentioned means including a pair of record engaging needles secured in spaced apart substantially parallel relation to said coupling member, said needles extending in opposite directions from said member along axes passing through the axis of rotation of said coupling member at substantially supplemental angles and to points beyond and clear of said support in a plane located at right angles to the length of the coupling member.

2. A pickup for playing opposite sides of double faced disc records, including in combination, a casing dening support, said casing being provided with an opening at each side thereof, a transducer including a mechanically actuated element mounted within said casing, a coupling member for mechanically actuating said element, said coupling member being mounted within said casing for limited rotation about an axis located lengthwise of the pickup and connected at one end to said element, and means for imparting movement to said coupling member when either side of said pickup is brought into position to engage a record, said last-mentioned means including a pair of record engaging needles secured in spaced apart substantially parallel relation to said coupling member, said needles extending in opposite directions from said member and through said openings along axes passing through the axis of rotation of said coupling member at substantially supplemental angles and to points beyond and clear of said support in a plane lo cated at right angles to the length of the coupling member.

3. A tone arm assembly of the type pivotally movable about an axis during the playing of a record, including in combination, a tone arm, a

pickup includinga Lcasing,"transducer means With- .,invsaid `casing, Aand needle means for actuating said transducer means, said needle means including a pair of record engaging needles mounted in spaced apart substantially parallel wrelation and operatively connected to said ,transducer means, said'needles .extending in oppositedirections from Within .said casingtopoints beyond and clear 'of said casing and substantial'lyin a' planejparallel .to thepivotal axis and at right angles totheitone arm whereby the points of said needles are equally distant from said axis.

4. A tone arm assembly of the type pivotally movable about an axis during the playing of a record, including in combination, a tone arm, a.

pickup including a transducer means, and needle means for actuating said transducer means, said needle means including a pair of record engaging needles mounted in spaced apart substantially parallel relation and operatively connected to said transducer means, said needles extending in 0pposite directions from said transducer means to points beyond and clear of said means and substantially in a plane parallel to the pivotal axis and at right angles to the major axis of the tone arm whereby the points of said needles are substantially equally distant from said pivotal axis.

5. A tone arm assembly of the type pivotally movable about an axis during the playing of a record, including in combination, a tone arm, a pickup including transducer means and la single transducer actuating element having a major axis extending generally outwardly from the pivotal axis, and a pair of record engaging needles secured to said actuating element in spaced apart relation along said major axis, said needles extending in opposite directions from said element to points beyond and clear of said transducer means and element and the spacing between the needles and the slant thereof being such that their points are more nearly in a plane passing through the element at right angles to said major axis than the points at which they are secured to said element.

6. A pickup shiftable to opposite sides of a record for playing opposite sides of records, including in combination, transducer means, a longitudinal transducer actuating element, yand a pair of record engaging needles secured in longitudinal spaced apart relation to said actuating element, said needles extending in opposite directions from said element to points beyond and clear 1of said transducer means and element and r, having their points in a plane located substantially at right angles to the longitudinal axis of said actuating element.

7. A pickup shiftable to opposite sides of a record and pivotally movable for playing opposite n sides of records. including in combination, trans- Iapart relation to said actuating element, said needles extending in opposite directions from said element to points beyond and clear of said transducer means and element and having their points nearer to each other longitudinally of said ele- 70 ment than the distance between the points Where the needles are secured to said element.

EDWARD F. ANDREWS.

(References on following page) REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 5 Number Name Date v1,034,387 Jetter July 30, 1912 1,270,526 Keen et al June 25, 1918 1,428,818 Sykes Sept. 12, 1922 10 Number Name Date Caputo Sept. 9, 1930 Thomas Feb. 26, 1935 Mueller Dec. 24, 1935 Wlelage July 13, 1937 Dally May 30, 1939 Andres Oct. 3, 1939 Bird Oct. 24, 1939 Schneider Sept. 1, 1942 Wissner May 11, 1943 

